Interaction Design

Interaction Design focuses on creating engaging, efficient, and intuitive interactions between users and digital products or systems. It is concerned with designing the way users interact with a product through various input methods (e.g., clicking, swiping, typing, voice commands). Interaction design ensures that the user experience feels natural, meaningful, and easy to navigate, guiding users through tasks with minimal confusion or frustration.

Interaction design is what you're actually experiencing every time you use a product that 'just feels right' — the transitions, the feedback, the way state changes are communicated visually. Poor interaction design makes technically capable products feel broken or unpolished. For founders, interaction design is often the hardest thing to articulate in a spec but the most noticeable when it's missing, and it's a primary driver of the 'I just prefer using X' sentiment that drives competitor switching.

Apple's rubber-band scroll (where content bounces slightly when you scroll past the edge) is a small interaction design detail that communicates physical boundaries in a virtual space — it has no functional purpose but makes the experience feel physical and satisfying in a way that a hard stop never could.